1. Field of the Invention
The present invention relates to method of controlling diesel engine for coping with an abnormality of an engine rotation sensor.
2. Description of the Prior Art
In controlling a fuel injection rate of a diesel engine through the electronic control, the condition of the engine and the condition of load, including the rotational speed of the engine, the opening of an accelerator and the engine water temperature and the like are detected by various sensors, a fuel injection rate is calculated from the results thus detected and a spill actuator (provided in a fuel injection pump) is controlled to select an actual fuel injection rate equalling to the calculated fuel injection rate.
As described above, in the electronic fuel injection control, the engine rotational speed is selected as one of the factors of control, and hence, when the engine rotation sensor is fallen into an abnormality, the fuel injection rate is always regarded as being based on the rotation speed of O. Because of this, the fuel injection rate should necessarily increase, with the result that there may occur an overrun of the engine, a reckless run of a vehicle or a damage of the engine.